The invention concerns a hormone combination for the stimulation of ovulation for hormonal control of the reproduction process in the raising of animals, and a method for the use of this combination.
Ovulation is physiologically induced through the hormone of the pituitary--hypophyse. Hypophyse is in turn regulated through control centers in the hypothalamus. (Doecke 1975)
For biotechnical and therapeutic stimulation and release of ovulation in animals, additional hormones are injected; these are derived from the serum of pregnant mares--PMSG--and the urine of pregnant women--HCG. If the injections are carried out simultaneously in a group of animals, an ovulation synchronization is effected, which can be employed in a wide range of contexts, such as in swine raising. (Huehn and coworkers, 1974; Prange and Bergfeld 1975; TGL No. 31709 Gr. 941250).
In these processes, the animals are first presynchronized, then treated with PMSG and finally with HCG prior to two artificial inseminations. The ovulation follows after about 42 hours from the HCG injection, but there is considerable variation, so that at a fixed insemination time not all cells are fertilized. Moreover, as PMSG and HCG are foreign protein preparations, with multiple applications the development of immunity cannot be completely excluded.
The gonadotropins PMSG and HCG enter the blood circulation after the injections and acts directly upon the ovaries. They thereby override or increase the activity of the hormones produced by the animals themselves. As the biotechnical control of the reproduction process makes possible a more intensive production of animal stocks, the range of applicability of the method of ovulation stimulation or release is quite broad. The possibilities of production for the required biological active substances, however, is limited and thus reduces the actual applications of the process.